摘要： 通过对现有的一些电子文档签名软件的功能和特点进行分析比较，结合最新的电子签名法的相关规定，根据签名文件交换过程中的特点和要求设计了一种新的文件封装格式，支持对文件和文件夹签名、多人签名。在这基础上设计和实现了追加式电子档案签名的原型系统，并为与其它业务系统的整合设计了接口，其中对实现过程中遇到的一些关键问题进行了分析说明。

关键词: 数字签名, 追加式, 多人签名

Abstract: According to the comparison and analysis of some existing signature software, the requirement of electric signature law and the specialty of file transferring, a new format of file encapsulation is designed, which supports cosigning and signing on files and folders. Based on the new format, the prototype of supplementary signature system is implemented; the interfaces are also designed for the purpose of joining with other business system easily. Finally, the key problems, which are encountered while developing, are put forward and explained.

Key words: Digital signature, Supplementary, Cosign